POS1327 AMYLOID STORM DEVELOPS IN PATIENTS WITH AA AMYLOIDOSIS AND ASSOCIATED WITH HIGHER AMYLOID BURDEN AND INCREASED MORTALITY
Authors: M. Bektaş, S. Sari, N. Koca, E. Oguz, B. Ince, Y. Yalçinkaya, B. Artim-Esen, M. Inanc, A. Gül
Journal: Annals of the Rheumatic Diseases (2022)

Background Amyloid storm is an emerging condition which was described recently also associated with poor prognosis in patients (pts) with AA amyloidosis (AA-a). Objectives We herein aimed to evaluate the amyloid storm and its associated factors in pts with AA-a. Methods We retrospectively evaluated AA-a pts who followed in our tertiary referral amyloidosis center. Diagnosis of AA-a was made by Congo red straning and immunohistochemistry. Amyloid storm was defined as follows; developing within two weeks, increase in creatinine and proteinuria levels at least two times from baseline or reach the CRP levels more than 10 times [1]. Results Data of 175 pts with AA-a were evaluated and after exclusion of 11 pts who had missing data, 164 pts were included into the analysis. We identified 9 pts (5.5%; of 4 male) who developed amyloid storm. Five pts were FMF-associated AA-a (FMF-AA) and 4 pts were non-FMF-AA (two pts had ankylosing spondylitis, one patient idiopathic and one patient non-FMF periodic fever syndrome) (p=0.1). Median±interquartile range (IQR) patient age, diagnosis age of FMF and amyloidosis were lower in pts had amyloid storm than had not, but they were not statistically different (p=0.2, p=0.3 and p=0.2 respectively). All pts were M694V homozygous among FMF-AA. Etiology of amyloid storm was infection in 5 pts (56%), treatment non-adherence in 3 pts (33%) and surgery in one patient (11%). Overall, 3 pts with amyloid storm died (33%), but mortality was 10% (n=16) in the remaining pts with AA-a. One patient died during the amyloid storm, and others died within one year after the diagnosis of amyloid storm (median 5 months). In univariable analysis, involvement of ≥3 organs, bone marrow involvement and current proteinuria levels (p=0.4, p=0.05 and p=0.04, respectively) were higher; median number of organ involvement and mortality (p=0.09 and p=0.07) were tended to be higher in pts with amyloid storm than those without it. End stage renal disease (ESRD) development was also higher in pts who had amyloid storm (67%; n=6) than in pts who had not (46 % n=71) but did not reach statistical significance (p=0.3). Median±IQR CRP (48 ±77 vs 9 ±17 p=0.08), creatinine (4.8 ±5 vs1.2 ±0.6 p=0.01) and proteinuria (11 ±12 vs 0.85 ±2.3 p=0.02) levels were higher during the amyloid storm than their previous records. In multivariable analysis, amyloid storm was associated with higher mortality (p=0.045 OR 4.6; 95 % CI 1.03-20). In survival analysis, development of amyloid storm tended to be higher in pts with non-FMF-AA compared to FMF-AA (Log-rank p=0.057). Mortality rate was higher in pts who had amyloid storm than those without it (Log-rank p=0.038). Conclusion This study showed that 5.5% of pts with AA-a may develop amyloid storm, and this condition was associated with higher amyloid burden. Amyloid storm may develop in AA-a pts associated with both FMF and other diseases, and the mortality rate may reach to 33% within one year. References [1]Kukuy et al. (2021). Rheumatology , 60 (7), 3235–3242 Table 1. Comparison of clinical and laboratory features of pts with and without amyloid storm Variables Amyloid storm (n=9) Control (n=155) p value Age* Ɨ 37±10 45±20 0.2 Gender, male # 4 (44) 86 (56) 0.7 Diagnosis # FMF 5 (4) 122 (96) 0.1 non-FMF 4 (11) 33 (89) Organ distribution # Renal 9 (100) 152 (98) 1 Gastrointestinal 4 (44) 33 (21) 0.1 Heart 2/6 (33) 32/111 (29) 1 Liver 1 (11) 5 (3) 0.3 Bone marrow 2 (22) 5 (3) 0.05 Diagnosis age of FMF* Ɨ 17.5±30 24±20 0.3 Diagnosis age of AA-a* Ɨ 26±26 31±22 0.2 Duration of AA-a* Ɨ 10±14.6 11.2±11 1 Number of organ involvement* 2±2 1±1 0.09 ≥3 organ involvement # 3/5 (60) 20/122 (16) 0.04 Baseline CRP* ĸ proteinuria (g/dL)* creatinine (mg/dL)* 10±85.3±4.30.8±0.6 20±204±5.70.8±0.6 0.060.90.6 Current CRP* ĸ proteinuria* creatinine* 2.7±5.2 3.1±231.5±3 2.7±7.3 0±1.90±1.9 0.7 0.04 0.04 Two exon 10 MEFV variant (n=108, %) 3 (100) 94 (87) 0.5 M694V homozygous (n=3, %) 3 (100) 73 (68) 0.2 ESRD development # 6 (67) 71 (46) 0.3 Mortality # 3 (33) 16 (10) 0.07 •.*median±IQR Ɨ years # (n, %) ĸ mg/L Figure 1. Comparison of survival rate between pts with and without amyloid storm Log-rank: p=0.038 Disclosure of Interests None declared